In electronic devices which are battery powered, it is often desirable to minimize battery drain by strobing ON and OFF certain components of the electronic device. An example of such electronic device is a portable communications receiver, such as a selective call receiver (pager). Certain portions of the receiver circuit in the selective call receiver are turned 0N and OFF in order to minimize battery drain. One such component of the receiver circuit is an amplifier, such as a transconductance amplifier, used in processing the received modulated signal.
The operating voltage of known prior art fully differential transconductance amplifier circuits with common-mode output voltage stabilization is not low enough to allow for operation from a single cell battery, which can have an end-of-life voltage of approximately 1 volt. This is especially important in portable electronic devices, many of which operate from a single cell battery.
It is desirable to provide a fully differential transconductance amplifier suitable for integrated circuit implementation with common-mode output voltage stabilization, which has a minimal warm-up time and provides a very low input offset voltage. It is further desirable to provide a fully differential transconductance amplifier whose gain is externally controllable, and which will operate from a single cell battery.